For exit light units, the Federal Aviation Regulations (FAR) require a fairly even light intensity distribution. In particular, the FAR set limit values for the ratio between the brightest portion of the exit light unit and the least bright portion of the exit light unit on the extended light emission surface. An exemplary limit value for this ratio is 3. In order to satisfy such limit values, prior art approaches have employed very complicated optical structures, commonly employing a large number of light sources. Such approaches have proven to be not satisfactory with respect to their efficiency and their reliability.
Accordingly, it would be beneficial to provide an interior aircraft light unit that is able to satisfy such light intensity ratio requirements, has an improved efficiency and has an acceptable reliability.